<?php
function checkMD($year,$month,$day){
    if($month<1||$month>12){
        return false;
    }
    if($day<1||$day>31){
        return false;
    }
    $days=array(0,31,28,31,30,31,30,31,31,30,31,30,31);
    if($day>$days[$month]){
        return false;
    }
    if(isYear($year)){
        print("您输入的是闰年！")
    }else{
        print("您输入的不是闰年！")
    }
    return true;
}
function isYear($year){
    if(($year%4==0 && $year%100!=0)||($year%100==0 && $year%400!=0)){
        return true;
    }else{
        return false;
    }
}
?>